// 判断参数是否是其中之一
export function oneOf (value, validList) {
  for (let i = 0; i < validList.length; i++) {
    if (value === validList[i]) {
      return true;
    }
  }
  return false;
}
// 驼峰变成小写加-
export function camelcaseToHyphen (str) {
  return str.replace(/([a-z])([A-Z])/g, '$1-$2').toLowerCase();
}

// For Modal scrollBar hidden
let cached;
export function getScrollBarSize (fresh) {
  if (fresh || cached === undefined) {
    const inner = document.createElement('div');
    inner.style.width = '100%';
    inner.style.height = '200px';

    const outer = document.createElement('div');
    const outerStyle = outer.style;

    outerStyle.position = 'absolute';
    outerStyle.top = 0;
    outerStyle.left = 0;
    outerStyle.pointerEvents = 'none';
    outerStyle.visibility = 'hidden';
    outerStyle.width = '200px';
    outerStyle.height = '150px';
    outerStyle.overflow = 'hidden';

    outer.appendChild(inner);

    document.body.appendChild(outer);

    const widthContained = inner.offsetWidth;
    outer.style.overflow = 'scroll';
    let widthScroll = inner.offsetWidth;

    if (widthContained === widthScroll) {
      widthScroll = outer.clientWidth;
    }
    document.body.removeChild(outer);
    cached = widthContained - widthScroll;
  }
  return cached;
}

// watch DOM change
export const MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver || false;

const SPECIAL_CHARS_REGEXP = /([\:\-\_]+(.))/g;
const MOZ_HACK_REGEXP = /^moz([A-Z])/;

function camelCase(name) {
  return name.replace(SPECIAL_CHARS_REGEXP, function(_, separator, letter, offset) {
    return offset ? letter.toUpperCase() : letter;
  }).replace(MOZ_HACK_REGEXP, 'Moz$1');
}
// getStyle
export function getStyle (element, styleName) {
    if (!element || !styleName) return null;
    styleName = camelCase(styleName);
    if (styleName === 'float') {
        styleName = 'cssFloat';
    }
    try {
        const computed = document.defaultView.getComputedStyle(element, '');
        return element.style[styleName] || computed ? computed[styleName] : null;
    } catch(e) {
        return element.style[styleName];
    }
}

// firstUpperCase
function firstUpperCase(str) {
    return str.toString()[0].toUpperCase() + str.toString().slice(1);
}
export {firstUpperCase};

// Warn
export function warnProp(component, prop, correctType, wrongType) {
    correctType = firstUpperCase(correctType);
    wrongType = firstUpperCase(wrongType);
    console.error(`[iView warn]: Invalid prop: type check failed for prop ${prop}. Expected ${correctType}, got ${wrongType}. (found in component: ${component})`);    // eslint-disable-line
}

function typeOf(obj) {
  const toString = Object.prototype.toString;
  const map = {
    '[object Boolean]'  : 'boolean',
    '[object Number]'   : 'number',
    '[object String]'   : 'string',
    '[object Function]' : 'function',
    '[object Array]'    : 'array',
    '[object Date]'     : 'date',
    '[object RegExp]'   : 'regExp',
    '[object Undefined]': 'undefined',
    '[object Null]'     : 'null',
    '[object Object]'   : 'object'
  };
  return map[toString.call(obj)];
}

// deepCopy
function deepCopy(data) {
    const t = typeOf(data);
    let o;

    if (t === 'array') {
        o = [];
    } else if ( t === 'object') {
        o = {};
    } else {
        return data;
    }

    if (t === 'array') {
      for (let i = 0; i < data.length; i++) {
        o.push(deepCopy(data[i]));
      }
    } else if ( t === 'object') {
      for (let i in data) {
        o[i] = deepCopy(data[i]);
      }
    }
    return o;
}

export {deepCopy};

// scrollTop animation
export function scrollTop(el, from = 0, to, duration = 500) {
  if (!window.requestAnimationFrame) {
    window.requestAnimationFrame = (
      window.webkitRequestAnimationFrame ||
      window.mozRequestAnimationFrame ||
      window.msRequestAnimationFrame ||
      function (callback) {
        return window.setTimeout(callback, 1000/60);
      }
    );
  }
  const difference = Math.abs(from - to);
  const step = Math.ceil(difference / duration * 50);

  function scroll(start, end, step) {
    if (start === end) return;

    let d = (start + step > end) ? end : start + step;
    if (start > end) {
        d = (start - step < end) ? end : start - step;
    }

    if (el === window) {
        window.scrollTo(d, d);
    } else {
        el.scrollTop = d;
    }
    window.requestAnimationFrame(() => scroll(d, end, step));
  }
  scroll(from, to, step);
}

// Find components upward
function findComponentUpward (context, componentName, componentNames) {
    if (typeof componentName === 'string') {
        componentNames = [componentName];
    } else {
        componentNames = componentName;
    }

    let parent = context.$parent;
    let name = parent.$options.name;
    while (parent && (!name || componentNames.indexOf(name) < 0)) {
        parent = parent.$parent;
        if (parent) name = parent.$options.name;
    }
    return parent;
}
export {findComponentUpward};

// Find component downward
function findComponentDownward (context, componentName) {
    const childrens = context.$children;
    let children = null;

    if (childrens.length) {
        childrens.forEach(child => {
            const name = child.$options.name;
            if (name === componentName) {
                children = child;
            }
        });

        for (let i = 0; i < childrens.length; i++) {
            const child = childrens[i];
            const name = child.$options.name;
            if (name === componentName) {
                children = child;
                break;
            } else {
                children = findComponentDownward(child, componentName);
                if (children) break;
            }
        }
    }
    return children;
}
export {findComponentDownward};

// Find components downward
function findComponentsDownward (context, componentName) {
    
    const components = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : [];
    const childrens = context.$children;

    if (childrens.length) {
        childrens.forEach(child => {
            const name = child.$options.name;
            const childs = child.$children;

            if (name === componentName) {
              components.push(child);
            }
            if (childs.length) {
                const findChilds = findComponentsDownward(child, componentName, components);
                if (findChilds) {
                  components.concat(findChilds);
                }
            }
        });
    }
    return components;
}
export {findComponentsDownward};